Method for producing fine glass articles and the use of said method

Abstract

A method for producing thin glass articles from low-viscosity glass, in particular of glass with viscosities n <10 dPas is presented, in which a thin-bodied glass composition is fed into a lower tool ( 1 ), and the glass composition is compressed by driving an upper tool ( 4 ), positioned opposite the lower tool ( 1 ), and the lower tool ( 1 ) together. The invention also relates to the use of the method. A method for producing thin glass articles is to be furnished, in which the problem of rapid cooling that occurs in the prior art is eliminated, so as to enhance the quality of the finished glass and to create the possibility of producing thin glass articles by means of pressing. The method according to the invention provides a remedy in that the surface roughness (R z ) of the tools ( 1, 4 ) is between 5 and 15 μm, and between the method step of “feeding” and the method step of “compressing” is preformed by forces of acceleration, accelerations between 1 and 10 G (acceleration due to gravity) being realized.

1 . A method for producing thin glass articles, in particular substrates, in particular hard disk substrates, spherical and aspherical lens arrays, and micro- and macrostructured bodies of low-viscosity glass, in particular of glass with viscosities n <10 dpas, in which a thin-bodied glass composition ( 2 ) is fed into a lower tool ( 1 ), and the glass composition ( 2 ) is compressed by driving an upper tool ( 4 ), positioned opposite the lower tool ( 1 ), and the lower tool ( 1 ) together, characterized in that the surface roughness R Z  of the tools ( 1 ,  4 ) is between 5 and 15 μm, and between the method step of “feeding” and the method step of “compressing” is preformed by forces of acceleration, accelerations between 1 and 10 G (acceleration due to gravity) being realized.  
     
     
         2 . The method of  claim 1 , characterized in that the glass gob ( 2 ) is preformed by vertically acting forces of acceleration.  
     
     
         3 . The method of one of the foregoing claims, characterized in that the glass gob ( 2 ) is preformed by a downward-oriented, abruptly decelerated and acceleration-inducing motion of the lower tool ( 1 ).  
     
     
         4 . The method of  claim 3 , characterized in that the maximum acceleration is achieved at the end of the lowering operation.  
     
     
         5 . The method of one of claims  1  or  2 , characterized in that the glass gob ( 2 ) is preformed by a upward-oriented, abruptly delayed and acceleration-inducing motion of the lower tool ( 1 ).  
     
     
         6 . The method of  claim 5 , characterized in that the maximum acceleration is achieved at the beginning of the upward motion.  
     
     
         7 . The method of one of the foregoing claims, characterized in that the glass melt is exposed essentially only to vertical forces between the method step of “feeding” and the method step of “compressing”.  
     
     
         8 . The method of  claim 7 , characterized in that the lower tool ( 1 ), for the feeding operation, is positioned below the feeder outlet ( 3 ), and the thin-bodied glass is fed in; that after the termination of the feeding operation the lower tool ( 1 ) is lowered vertically, together with the fed-in glass gob ( 2 ), as far as a lower position of repose; and that the upper tool ( 4 ), located in a parking position during the feeding operation, is introduced into the interstice ( 5 ) formed between the feeder outlet ( 3 ) and the lower tool ( 1 ) by the lowering of the lower tool ( 1 ), the upper tool ( 4 ) being fixed for the pressing operation, and the glass gob ( 2 ) is pressed into form by the upward motion of the lower tool ( 1 ) in the direction of the thus-fixed upper tool ( 4 ).  
     
     
         9 . The method of  claim 7 , characterized in that the lower tool ( 1 ), for the feeding operation, is positioned below the feeder outlet ( 3 ), and the thin-bodied glass is fed in; that after the termination of the feeding operation the lower tool ( 1 ) is lowered vertically, together with the fed-in glass gob ( 2 ), as far as a lower position of repose; and that the upper tool ( 4 ), located in a parking position during the feeding operation, is introduced into the interstice ( 5 ) formed between the feeder outlet ( 3 ) and the lower tool ( 1 ) by the lowering of the lower tool ( 1 ), wherein by downward motion of the upper tool in the direction of the lower tool ( 1 ) which is fixed for the pressing operation, the glass gob ( 2 ) is pressed into form.  
     
     
         10 . The method of one of claims  8  or  9 , characterized in that the upper tool ( 4 ) during the feeding operation is parked laterally and thus at the same height as the interstice ( 5 ) embodied between the feeder outlet ( 3 ) and the lower tool ( 1 ) by the lowering of the lower tool ( 1 ), and for the pressing operation the upper tool is positioned by a lateral, essentially horizontal inward shift or inward pivoting into the interstice ( 5 ) above the lower tool ( 1 ).  
     
     
         11 . The use of a method of one of claims  1 - 10 , characterized in that the method is used for producing electrically insulating carrier plates for electrical circuits and components, especially substrates for printed circuit boards, and for substrates on which electrical circuits are printed.  
     
     
         12 . The use of a method of one of claims  1 - 10 , characterized in that the method is used for producing hard disk substrates.